This is a custom built rifle, not a stock armalite. Only thing made by armalite on this rifle is the stripped upper receiver and the lower parts kit. The upper was made by Accuracy Systems Inc. I built the lower using an iron ridge billet lower and a armalite national match grade parts kit. I don't think frog lube would cause pierced primers. I have a feeling my gun either doesn't like this ammo, the firing pin/port is off, or possibly the headspace. But I feel like a headspace issue would of cause far more problems.
You welcome. This is our job to see if we can help each other.
The headspace in 7.62x51 has larger tolerances and even if it was on the large side the brass is designed to take it w/o any issues.
The only problem here is with very old military chambers like found in surplus FAL and even some early M14's / M1A converted that some folks found didn't pass the field gauge check or otherwise found out the hard way if you know what i mean.
Also an upper built by Accuracy Ssytem shoud be dead on. I mean you can try for your own peace of mind but I am sure that is not
the problem. however measure the firing pin protrusion and don't discard the ammo problems. I had batches of expensive Match Ammo
factory new blowing off primers. so imagine military surplus. Something very rare but it happends.
Again measure the protrusion.